Steering device for boats



Oct. 29, 1968 A. J. BURKE STEERING DEVICE FOR BOATS 5 Sheets-Sheet 1Original Filed Jan. 5, 1966 INVENTOR ARTHUR .z BURKE M70-4RM 7AM W5ATT/RNEYS Oct. 29, 1968 A. J. BURKE STEERING DEVICE FOR BOATSsheets-Sheet 2 Original Filed Jan. 5, 1966 ATT RNEYS ct. 29, 1968 A J,BURKE STEERING DEVICE FOR BOATS 3 Sheets-Sheet 5 Original Filed Jan. 5,1966 Pn/0T Axis oF RUDDER se INYENTOR ARTHUR BUR/(E BY Mm, M

' d AgoRNEYs United States Patent O 3,407,774 STEERING DEVICE EUR EGATSArthur I. Burke, 28 Andrews Ave., (iakland, NJ. 074136 Continuation ofapplication Ser. No. 518,929, dan. 5, 1966. This application Aug. 22,1967, Ser. No.

6 Claims. (Cl. 1114-163) ABSTRACT GTF THE DSCLGSURE Related applicationThis application is a continuation of my co-pending application Ser. No.518,929, filed Ian. 5, 1966, now abandoned, for Steering Device `forBoats.

This invention relates to steering devices for waterborne vehicles andis particularly concerned with a novel marine steering device forimproving the maneuverability of single-screw, fast-planing boats whenbacking down.

Fast-planing, single-screw boats of the type which this invention isespecially concerned with, have a minimum of parts protruding downwardlyfrom the hull bottom to minimize resistance and thus provide for a highforward speed with an inexpensive drive. These downwardly protradingparts usually are limited to a small keel, the propeller and shaftassembly, a shaft support strut, and the rudder. When moving forwardlyin boats of this type, the propeller pushes the water past the rudder tothereby make the rudder effective for maneuvering the boat. In reverse,however, there is only a very small vertical surface against which thepropeller wash is directed with the result that the maneuverability ofthe boat is degraded.

Typically, the stern of a fast-planing, single screw boat tends to go toport when equipped with a righthand screw. This occurs even with theslightest reverse motion of the boat and is the result of a swirlingmass of water which is driven forwardly against the bottom of the hullby the propeller. The water in this mass, when looking forwardly, movescounterclockwise around the propeller shaft and exerts a force on thehull and the propeller shaft support strut to push the stern to port.This mass of water also exerts a force on the hull bottom to slowreverse motion of the boat since it opposes the suction force of thepropeller.

Prior to this invention, some proposals have been made for improving themaneuverability of a boat when backing down, but none are satisfactoryfor fast planing boats of the type described above since they all haveadditional control surfaces protruding from the bottom of the hull whichare of such size and which are in such locations as to objectionablyimpede the boats forward speed. Some of these prior devices involveunbalanced rudder surfaces which are retractable to an inoperativeposition within the boat when moving in a forward direction. This,however, requires a specially constructed hull and expensive apparatusfor retracting the rudders. The retractable rudder arrangement thus isentirely unsuitable and impractical for use in the standard inboardrunabouts, utilities, sport fishermen, sedans, and cruisers in thecousumer market.

In overcoming the foregoing problems, the major object of this inventionis to provide for a novel steering device for improving themaneuverability of a boat without objectionably impeding its forwardspeed capabilities.

A more specific object of this invention isvto provide a single-screwboat with a novel sternway rudder steering device which is located justforwardly of a conventional rudder and screw and above the propellershaft and which has a control surface in the wash of the propeller whenbacking down.

By confining the sternway rudder device of this invention to the regionabove the propeller shaft, negligible turbulence, if any, is produced inthe stream of water leading to the propeller when the boat is moving ina forward direction. As a result, the forward speed of the boat is notdiminished. When backing down, the rudder device of this invention andthe conventional rudder, which is aft of the propeller, are operativelyconnected so that their movement is correlated and unitary.

Still another object of this invention is to provide a novel sternwaymarine steering device which is simple in construction, inexpensive tomanufacture and install, and requires little or no maintenance.

A further object of this invention is to provide a novel sternwaysteering device which is in a protected location vertically above thepropeller shaft and below the boat hull where it does not constitute anobjectionable obstruction to streamline flow of water around the hull.

Another object of this invention is to provide a novel sternway steeringdevice which is easily added as an accessory to the steering system of aboat without interfering with the basic stability of the system.

Further objects of this invention will appear as the descriptionproceeds in connection with the annexed claims and appended drawingswherein:

FIGURE 1 is a side elevation of a boat incorporating the sternwaysteering device of this invention and illustrating the hull to be brokenaway to show interior details;

FIGURE 2 is a section taken substantially along lines 2-2 of FIGURE 1and illustrating the motion transmitting linkage operatively connectingthe main rudder to the sternway rudder of this invention;

FIGURE 3 is a fragmentary section in elevation illustrating a modifiedembodiment of this invention;

FIGURE 4 is a fragmentary elevation illustrating another embodiment ofthis invention;

FIGURE 5 is a fragmentary elevation illustrating still anotherembodiment of this invention;

FIGURE 6 is a section taken substantially along lines 6 6 of FIGURE 5and showing the sternway rudder device of this invention positioned forsternway Steerage to starboard; and

FIGURE 7 is a partially schematic view looking from starboard towardport for comparing the differences in steering control achieved by therudder in FIGURE 5 and the rudder in FIGURE l.

Referring now to the drawings, and more particularly to FIGURE l, thereference numeral lil generally designates a power driven, single-screwboat having a conventional, fast planing hull l2 which may be formedwith a keel i4 of minimum depth. Boat 10 may be of any inboard type suchas, for example, a runabout, a utility vessel, a sport fisherman, asedan, or a cruiser and is shown to have Ia suitable engine 16 mountedin hull 12.

With continuing reference to FIGURE 1, engine 16 is operativelyconnected through a conventional transmission gear box 17 to a propellershaft 18 which extends rearwardly through the bottom of hull 12. Theportion of shaft 18 projecting from the bottom .of hull 12 is shown tobe inclined downwardly at an acute angle with respect to the horizontaland is spaced below the bottom of hull 12 at the stern of the vessel.Gear box 17 may be of any main steering rudder 26 is mounted on avertical rudder- A post 28 which extends through hull l2 and which isrotatably supported about an axis intersecting or passing closelyadjacent to the rotational axis of shaft 18. Rudder 26 is disposedadjacent to and rearwardly of propeller so that its steering controlsurfaces are located directly in the propeller wash when gear box i7 isshifted to its forward drive. Any suitable means such as a wheel 3d isoperatively connected to rudderpost 28 as by a motion transmitting cable32 to swing rudder 26 about the axis of rudderpost 28 for steering theboat in a known manner.

The boat construction thus far described is conventional and is known toprovide for high forward speeds owing to the conguration of hull l2 andthe minimum number and size of parts projecting downwardly from thebottom of the hull l2. In this embodiment only rudder 26, shaft 13,strut Ztl, and keel ld provide the major surfaces on which the wateracts to resist the driven `motion of the boat. It will be appreciatedthat hull l2 may also be formed without a keel.

This type 4of boat typically is difficult to maneuver when backing downsince there is a minimum of vertical surface against which the propellerwash can be directed. Without the incorporation of this invention, thestern of such boats tend to go to port when equipped with a right-handpropeller. This is the result, as previously 2 mentioned, of a mass ofwater swirling around shaft i8 partially in the same direction ofpropeller rotation and moving forwardly against the bottom of hull l2 inthe region of shaft 18. The rotation of this mass of water swirling in acounterclockwise direction and acting on hull i2 and struct Ztl tends topush the stern of the boat to port.

In accordance with this invention, a sternway steering control device isprovided to overcome these problems of maneuverability when backing downand is shown in FIGURE 1 to comprise a fiat-sided sternway rudder 36which is mounted on the lower end of a vertical rudderpost 3S.Rudderpost 38 preferably is parallel with rudderpost 2S and is shown toextend through hull l2 along an axis substantially intersecting the axisof shaft i8 forwardly of strut 2i). A bearing and seal collar 39 boltedto hull 12 rotatably mounts rudderpost 38. The axes of rudderposts 28and 3S and shaft 18 preferably are contained in a common vertical planeand are located substantially midway between opposite sides of hull l2.

As shown, rudder is formed with fiat, parallel, oppositely facingsteering control surfaces and is located completely above shaft l?) inthe space delimited by strut 20, the bottom of hull l2, and shaft iii.Thus located, it is clear that -rudder 36 is directly in the wash ofpropeller 24 when reversed to cause sternway movement. ireferably rudder33 is of the partially balanced type having steering control surfacesfore and aft of the rudderpost axis.

The upper end of Arudderpost 33 extending above collar 39 is connectedto rudderpost 2S by a suitable motion transmitting linkage il which, asshown in FIGURE 2, may comprise a pair of arms 42 and 4d and a rigidlink 46. Arms 42 and 44 `are respectively iixed to rudderposts 28 and 38and pivotally connected by pins 47 to opposite ends of link 46. Withthis construction, it is apparent that the movement of rudders 2r? and36 are correlated and unitary.

Rudders 26 and 36 are so connected by assembly dit that they are rotatedin the same direction about the axes of their respective rudderposts andare essentially both centered in a given position of wheel 36. Althoughrudders 26 and 36 may be connected to move in substantially parallelplanes, it is preferable that rudder 36 slightly oversteers rudder 26 toimprove the maneuverability of the boat when backing down.

Advantageously, one of the pins 47 is removable to disconnect rudder 36from rudder 26. Suitable uushown means may be employed to lock rudder 36in its centered position when disconnected from rudder 26.

During sternway movement, the increased vertical steering controlsurface provided by rudder 36 directly in the propeller wash counteractsthe tendency of the stern of the boat to go to port since the force ofthe forwardly moving mass of water swirling around shaft 18 acts onrudder 36 to move the boat in a starboard direction. In effect, rudder36 atords the same stability in steering during sternway movement asdoes rudder 26 for forward movement. When backing down and beforesternway movement takes place, it has been found that rudder 36 providesfor maximum effectiveness when turned to one extreme position or theother. This apparently is due to the fact that the flow lines in theforwardly moving mass of water swirling around shaft 18 become lessaxial as sternway movement is decreased. Thus, by turning rudder 36 toeither of its extreme port or starboard positions, a maximum projectedrudder control surface arca is presented to the axial component of thepropeller wash to thereby obtain the maximum control action offered byrudder 36 before sternway movement begins.

Ey locating rudder 36 in a region of turbulent iiow around hull l2, theresistance oifered by rudder 36 to high forward speeds is insignificant.Furthermore, confinement of rudder 36 to a position vertically aboveshaft 18 as shown in FIGURE l adds little, if any, turbulence to thestream of water leading to propeller 24 when the boat is moving in aforward direction. Accordingly, it is evident that the sternway ruddercontrol device of this invention does not compromise the forward speedcapabilities of the boat and is located in such a position as to providefor maximum control with a minimum of rudder surface area. Since rudder36 is of a partially balanced construction, it does not materially alterthe basic stability of the steering system in either forward or sternwaytravel. To further increase the maneuverability of the boat when backingdown, a rudder extension (FIG- URE 4) may be secured to rudder 36 by asuitable bracket assembly 56 to extend below propeller shaft 18. Thisrudder extension, however, increases the resistance to forward movement.

Compared with the vulnerable location of [rudder 26, rudder 36, beingconfined in the space delimited by shaft 18, strut 26, and hull l2, isprotected against damage. Should rudder 26 become damaged, it may bedisconnected from rudder 36 which then may be used to provide somecontrol for forward steering in an emergency.

FIGURE 3 illustrates a modified embodiment of this invention wherein asternway rudder 60 is incorporated as part of a propeller shaft supportstrut assembly 62. Assembly 62 is shown to comprise a cylindrical post64 which is fixed to and extends downwardly from the bottom of hull i2along an axis intersecting the rotational axis of shaft 1S. The lowerend of post 64 is rigidly fixed to a sleeve 66. Shaft 18 coaxiallyextends through sleeve 66 and is journalled therein by a suitablebushing 68.

Still referring to FIGURE 3, post 64 coaxially extends through a ruddermounting sleeve 70 and terminates at its upper end in an enlarged headwhich is seated on the upper end of sleeve 7 ti within hull 12. Theupper portion of sleeve '70 is journalled in a bearing and seal collar72 by a suitable sleeve bushing 74. Collar 72 is bolted in place withinhull 12. A key 76 or other suitable means carried by sleeve 70 isdisposed axially between collar 72 and arm d4 to axially retain sleeve70 and post 64 in place. Rudder 66 is fixed to sleeve 70 which isrotatable about the axis of post 64. The lower end of sleeve 70 isseated on a boss portion formed integral with sleeve 66.

As shown, rudder 60 is disposed just forwardly of propeller 24 so thatit is very close to and directly in the propeller wash when gear box 17is shifted to its reverse position for sternway movement. Thus located,rudder 60 provides for exceptional steering control when backing down.Rudder 60 preferably is partially balanced as shown. Operation of rudder60 for controlling sternway movement is the same as that explained forrudder 36.

FIGURES 5 and 6 illustrate a modified sternway rudder assembly having arudder 100 mounted on a rudder post 102. Post 102 extends through thehull of boat 10 and is adapted to be connected by linkage 40 to rudder26 in the manner described in the previous embodiments. Rudder 100 isdisposed in the space vertically above shaft 18 and forwardly of strut20 similar to the embodiment illustrated in FIGURE l. The axis of post102 intersects or is closely adjacent to the axis of shaft 18.

In the embodiment of FIGURES 5 and 6, the post 102 and rudder 100 areinclined rearwardly such that the axis of post 102 is at an acute anglewith a vertical plane and more normal with respect to the downwardlyinclined axis of shaft 18 as compared with the sternway rudder of FIG-URE 1. The rearward edge of rudder 100 is thus tilted downwardly.

The portion of rudder 100 that is to the stern of the axis of post 102is provided with larger steering control surface areas than that whichis disposed forwardly of the rudder post axis. As a result, the rearwardportion of rudder 100 has a correspondingly greater effect on steeringthan the forward portion thereof. The forward portion of rudder 100provides a partially balanced condition when the rudder is turned ineither direction from its cen tered position to improve the stability insteerage and to thus prevent the triggering of sudden movements of theboat when backing down.

Propeller 24, as previously described, is a right-hand screw whichproduces a forwardly moving, swirling mass of water. The part of thismass of water which influences rudder 100 directly is shown to be incylindrical form and is indicated at 104. By inclining rudder 100 in themanner illustrated in FIGURE 5, the rudder control surface disposedrearwardly of the rudder axis is impinged by the largest amount of mass104 possible for the limited height between shaft 18 and the boat hull.As shown, the Ipivot axis of rudder 100 is tilted in a direction that atleast approaches perpendicularity with the mean or average direction offlow in mass 104.

The effective height of the control surface of rudder 100 which isdisposed rearwardly of the rudder axis and which is closely at rightangles to the average or mean direction of flow in mass 104 is indicatedby dimension a in FIGURE 7. Dimension b indicates the correspondingeffective height of rudder 36 which is normal to the average directionof flow in mass 104. It will be observed that the direction of flowthroughout mass 104 is not exactly uniform. Direction of flowimmediately adjacent to shaft 18, for example, is more axial than thedirection of flow at a radius equal to that of propeller 24. Also, theflow components in elevation and in a vertical plane containing the axisof shaft 18 are essentially parallel to shaft 18, whereas elevationalflow components contained in parallel vertical planes spaced laterallyto the starboard side of shaft 18 are upwardly inclined relative toshaft 18. Accordingly, the average or mean direction of these flow linesimpinging against rudder 100 is herein considered in explanation of thesignificant improvement in steerage control achieved by using `aninclined sternway rudder.

Since dimension ais appreciably greater than dimension b, as shown inFIGURE 7, a more effective sternway control to starboard is obtainedwith rudder 100 as compa-red with a rudder that is not inclined.

While improving sternway Steerage to starboard, the

tilting of rudder renders sternway Steerage to port less effective ascompared with the control obtained by employing rudder 36. When usingrudder 100, however, the overall control to port is effectively balancedwith the control to starboard as la result of the influence of thepropeller wash on the boat hull when propeller 24 is reversed to `backdown. By inclining rudder 100, therefore, effective use is `made of thenatural tendency of the boat to go to port to provide a balancedsternway control action in port and starboard directions. Similar to theembodiment of FIGURE 4, rudder 100 also may be provided with anextension disposed below shaft 18.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be lconsidered in all respects asillustrative `and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the `meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. In combination with a single screw, power driven boat having a hull,a propeller shaft protruding from the bottom of said hull, meanssupporting said shaft from said hull for rotation about an axisextending longitudinally of said hull, a propeller mounted on said shaftat the stern of said hull, and a steering rudder disposed rearwardly ofsaid propeller, 'the improvement of a sternway steering control devicecomprising a. rudder member disposed forwardly of said propeller and inthe propeller lwash when said propeller is rotated in a direction toback down, said rudder member being mounted for selective swingingmovement about an axis that is tilted from a vertical plane in adirection at least approaching perpendicularity with the mean directionof rising flow lines in the propeller wash.

2. The combination dened in claim 1 wherein the rotational axis of saidrudder, said rudder member, and said shaft are contained in asubstantially common, vertical plane medially intersecting said hull.

3. The combination defined in claim 1 wherein in addition to said ruddermember the parts projecting downwardly from said hull essentiallyconsist of said shaft, said propeller, said rudder, a strut supportingsaid shaft and a relatively small keel disposed only forwardly of saidrudder member, the combined area of the vertically oriented surfaces ofsaid shaft, said propeller, said rudder, said strut, and said keel beingsufficiently small that in absence of the Steerage control provided bysaid rudder member said -boat has a tendency to move either to port orstarboard when the propeller rotation is reversed for imparting sternwaymovement to said boat, the operation of said rudder member beingeffective to compensate for said tendency.

4. The combination defined in claim 3 comprising means operativelyconnecting said rudder and said rudder member together for unitarymovement, said rudder member being disposed completely above said shaftand in the space delimited by said hull, said shaft and said strut, withthe rotational axis of said rudder member sub stantially intersectingthe rotational axis of said shaft.

5. The combination defined in claim 3 wherein said shaft is tilted`downwardly from said hull at an acute angle with a horizontal plane andwherein the rearward edge of said rudder member is `also tilteddownwardly, said rudder member having steering control surfaces disposedboth rearwardly and forwardly of the rudder member rotational axis, thearea of the rearwardly disposed surfaces being greater than the area ofthe forwardly disposed surfaces, the inclination of said rudder memberbe` ing effective to increase the height of its Steerage controlsurfaces which at least approach perpendicularity with the meandirection of rising ow lines in the wash produced by reversely rotatingsaid propeller.

6. A sternway Steerage control device for a power 'driven boat having ap'ropeller rotatably supported from the stern of said hull, saidsternway Steerage contr-ol device comprising a rudder member disposedjust Vforwardly of said propeller and in the propeller wash when saidpropeller is reversely rotated for imparting sternway movement to `saidboat, said rudder member being mounted for selective swinging movementabout an axis that is tilted from a Vertical plane in a direction atleast approaching References Cited UNITED STATES PATENTS 6/1929 Ward114-163 9/1958 Scott 114-163 10 ANDREW H. FARRELL, Primary Examiner.

